I am one of them now. I found that riding to work is good in a few ways:
1. It saves me $$$ on gym membership. I am actually doing exercise on the way to work and on my way home.
2. It saves me $$$ on car space, petrol and toll.
3. Even I have a car space in North Sydney, It is 15 minutes walking distance away from the office. Riding a bike to work, I can park in the basement and get to the office by a lift. No walking distance!

With more and more cycleways built in Sydney, I am sure more and more people will ride to work. I think I am lucky that where I work provide shower facilities.